A perfect ring of dark green grass, six to eight feet across showed plainly on the springy turf of the salt-sprayed cliff; the Celtic fairies had been dancing. Often when the ring is clear enough there is no sign of the fairy which made it, but in this case there were hundreds of the tan-capped champignons all around the ring, for the fairy is a small edible fungus. A single toadstool starts the ring, its spawn spreading outwards. Where a toadstool has lived and died others will not live, so only the spawn on the outer side reproduces toadstools. So year by year the ring grows outwards, and though no fungus shows inside the ring, the grass which springs up is improved rather than damaged by the former occupation. The circle is not always perfect; indeed, it is often little more than an arc. As a rule fairy rings are more noticeable in August and September than in October.